Need some advice about an ex coming back... What should I do?

So there's this guy that i met on online dating back in February so like 4 months ago. And I went out with him on 1 date. Then for some reason ahe broke things off. He then came back at me in May saying there was this miscommunication and he said i thought i wasn't interested. I totally was like no i thought you werent interested bc you broke things off with me. Then he kept texting but never made plans to ask me out or make any effort to call, talk, communicate.. just flirting but i guess there's nothing wrong with that.. i just prefer more regular conversation like books movies and music we are into, how our lives are going... stuff like that. Anyway i felt like he wasn't giving me what i needed to i was like i had enough i couldnt take the mixed signals and bad communication. So i said good bye and good luck because i felt like he wasn't putting enough effort into it. Now, about a week ago today he messages me on the online dating site that we first started talking on. I can't see the message because you have to pay to read your messages. but i found out that he sent me a message from a notification on my phone. So now i am like He sends me this message on the dating site after i already tried breaking things off with him because i was so upset and confused. I dont understand why he is messaging me again. I thought it could be because he misses talking to me or he could just be bored and want to get under my skin again or have some banter back and forth like i had been doing, however this time i won't be allowing him to do that, use me like that. But i dont know if i should text him (still have his number from before) and let him know i am not on the site anymore and can't read messages because of my financial situation. I thought i would because it seems like maybe he could have learned things i will put up with and maybe he could be like Im sorry i messed up or something, i dont know. What should i do?